Telephone systems which translate a dialed telephone number into a routing number for routing a telephone call are well known in the art. For example, toll-free or "800" number calls involve translating a dialed 800 number into a number for routing calls to an 800 number subscriber. The translation is performed by querying a database maintained by the telephone service provider, such as an 800 number database of an interexchange carrier, to determine a routing number for routing the call.
Recent advances in processing telephone calls in which the dialed number is translated into a routing number for call routing have enabled the translation process to be controlled in part by the subscriber. In such systems, referred to herein as "Intelligent Call Processing" (ICP) systems, the subscriber maintains its own database to store routing instructions for selected special service calls. The subscriber's database is queried by a processor (also referred to herein as a "Network Control Point" or "NCP") in the communication system, at an appropriate point in call processing, to return routing instructions. The subscriber's database returns routing instruction information to the NCP, which in turn, provides call routing instructions to telephone switches within the communication system.
Intelligent Call Processing systems provide a subscriber with improved call handling ability and increased flexibility. However, sometimes calls cannot be processed and routed according to instructions from the subscriber's database, and the subscriber does not have sufficient information to determine when, how often, or why this occurs. For example, if the subscriber's database does not respond to a query for instructions within a prescribed time period, the call is routed according to default routing instructions that are stored within the NCP. Similarly, default routing instructions are used when instructions returned by the subscriber's database in response to a query are not in a format recognizable to the NCP. Under these circumstances, the subscriber has no way to verify whether calls are being routed as the subscriber intends, and thus cannot determine how well the system is working.